What if the only way to diagnose high blood pressure was to have a heart attack? Until recently, that was similar to the state of affairs for osteoporosis, a disease that affects 25 million Americans, including half of all women over the age of 45. Before the mid-80s, doctors could only diagnose the disease if you fractured a bone or lost more than two inches of height. The first bone densitometry tests were conducted in the early 1970s on astronauts as they trained for the Apollo space shuttle launch. A general x-ray test measured astronauts bone density, but the tests were far less accurate and used more radiation than the tests of today. “It was purely guesstimations compared to what we know now,” says John Monk, chief technologist at HealthEast Osteoporosis Services in St. Paul, Minn Those tests were never approved for general patient use. The Dual-Energy X-ray Absorptiometry (DEXA) scan was born in the mid-eighties. DEXA machines can diagnose and assess the progression of this common—and preventable—disease. While CT scans are sometimes used for the same purpose, they use far more radiation and cost far more money than DEXA tests. DEXA is more accurate than a routine cholesterol or blood pressure test. And it might be the easiest test you’ll ever take. All you have to do is wear comfortable clothes and lie flat on your back for about 10 minutes as the “arm” of the machine moves over your body.
Since the mid-90s, the test has become much more common and its uses have expanded. Monk said that six years ago, about 10-15 physicians referred him 10-15 patients a week. Now, 120 doctors refer patients to him and he sees 18-20 a day. And the machines, which are manufactured by companies such as Lunar, a division of GE Medical, and Hologic, have become more common. Monk estimates that there are now six or seven in St. Paul compared with two or three only a few years ago.
Demand for DEXA has increased as people realize that “it’s not an elderly disease anymore,” he says. Most patients used to be in their 60s or 70s, but now many middle aged men and women are coming in to get tested. The youngest person Monk has ever tested was six years old. He uses DEXA to test for congenital growth problems like osteogenesis imperfecta. The machine can detect whether bones are growing properly.
“It’s getting more broad than ever,” Monk says.
In addition to scanning, technologists discuss prevention and treatment with their patients. Osteoporosis can be prevented and even reversed with diet and exercise, which makes early detection all the more important.
